bpf: BTF support for ksyms #1
Closed
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
ksym so that further dereferences on the ksym can use the BTF info to validate accesses. Internally, when seeing a pseudo_btf_id ld insn, the verifier reads the btf_id stored in the insn[0]'s imm field and marks the dst_reg as PTR_TO_BTF_ID. The btf_id points to a VAR_KIND, which is encoded in btf_vminux by pahole. If the VAR is not of a struct type, the dst reg will be marked as PTR_TO_MEM instead of PTR_TO_BTF_ID and the mem_size is resolved to the size of the VAR's type. From the VAR btf_id, the verifier can also read the address of the ksym's corresponding kernel var from kallsyms and use that to fill dst_reg. Therefore, the proper functionality of pseudo_btf_id depends on (1) kallsyms and (2) the encoding of kernel global VARs in pahole, which should be available since pahole v1.18. Signed-off-by: Hao Luo <[email protected]> --- include/linux/bpf_verifier.h | 4 ++ include/linux/btf.h | 15 +++++ include/uapi/linux/bpf.h | 38 ++++++++--- kernel/bpf/btf.c | 15 ----- kernel/bpf/verifier.c | 112 ++++++++++++++++++++++++++++++--- tools/include/uapi/linux/bpf.h | 38 ++++++++--- 6 files changed, 182 insertions(+), 40 deletions(-)
information from kernel btf. If a valid btf entry for the ksym is found, libbpf can pass in the found btf id to the verifier, which validates the ksym's type and value. Typeless ksyms (i.e. those defined as 'void') will not have such btf_id, but it has the symbol's address (read from kallsyms) and its value is treated as a raw pointer. Signed-off-by: Hao Luo <[email protected]> --- tools/lib/bpf/libbpf.c | 116 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 102 insertions(+), 14 deletions(-)
the other is a plain int. This tests two paths in the kernel. Struct ksyms will be converted into PTR_TO_BTF_ID by the verifier while int typed ksyms will be converted into PTR_TO_MEM. Signed-off-by: Hao Luo <[email protected]> --- .../testing/selftests/bpf/prog_tests/ksyms.c | 31 +++------ .../selftests/bpf/prog_tests/ksyms_btf.c | 63 +++++++++++++++++++ .../selftests/bpf/progs/test_ksyms_btf.c | 23 +++++++ tools/testing/selftests/bpf/trace_helpers.c | 26 ++++++++ tools/testing/selftests/bpf/trace_helpers.h | 4 ++ 5 files changed, 123 insertions(+), 24 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/ksyms_btf.c create mode 100644 tools/testing/selftests/bpf/progs/test_ksyms_btf.c
bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the kernel except that it may return NULL. This happens when the cpu parameter is out of range. So the caller must check the returned value. Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Hao Luo <[email protected]> --- include/linux/bpf.h | 3 ++ include/linux/btf.h | 11 ++++++ include/uapi/linux/bpf.h | 17 +++++++++ kernel/bpf/btf.c | 10 ------ kernel/bpf/verifier.c | 66 +++++++++++++++++++++++++++++++--- kernel/trace/bpf_trace.c | 18 ++++++++++ tools/include/uapi/linux/bpf.h | 17 +++++++++ 7 files changed, 128 insertions(+), 14 deletions(-)
helper always returns a valid pointer, therefore no need to check returned value for NULL. Also note that all programs run with preemption disabled, which means that the returned pointer is stable during all the execution of the program. Signed-off-by: Hao Luo <[email protected]> --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 14 ++++++++++++++ kernel/bpf/verifier.c | 10 +++++++--- kernel/trace/bpf_trace.c | 14 ++++++++++++++ tools/include/uapi/linux/bpf.h | 14 ++++++++++++++ 5 files changed, 50 insertions(+), 3 deletions(-)
kernel. If the base pointer points to a struct, the returned reg is of type PTR_TO_BTF_ID. Direct pointer dereference can be applied on the returned variable. If the base pointer isn't a struct, the returned reg is of type PTR_TO_MEM, which also supports direct pointer dereference. Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Hao Luo <[email protected]> --- .../selftests/bpf/prog_tests/ksyms_btf.c | 10 +++++++ .../selftests/bpf/progs/test_ksyms_btf.c | 26 +++++++++++++++++++ 2 files changed, 36 insertions(+)
|
Master branch: 95cec14 patch https://patchwork.ozlabs.org/project/netdev/patch/[email protected]/ applied successfully |
|
At least one diff in series https://patchwork.ozlabs.org/project/netdev/list/?series=199405 expired. Closing PR. |
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 14, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 15, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 15, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 15, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 15, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kernel-patches-bot
pushed a commit
that referenced
this pull request
Sep 15, 2020
[ 6525.735488] Unexpected kernel BRK exception at EL1 [ 6525.735502] Internal error: ptrace BRK handler: f2000100 [#1] SMP [ 6525.741609] Modules linked in: nls_utf8 cifs libdes libarc4 dns_resolver fscache binfmt_misc nls_ascii nls_cp437 vfat fat aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce gf128mul efi_pstore sha2_ce sha256_arm64 sha1_ce evdev efivars efivarfs ip_tables x_tables autofs4 btrfs blake2b_generic xor xor_neon zstd_compress raid6_pq libcrc32c crc32c_generic ahci xhci_pci libahci xhci_hcd igb libata i2c_algo_bit nvme realtek usbcore nvme_core scsi_mod t10_pi netsec mdio_devres of_mdio gpio_keys fixed_phy libphy gpio_mb86s7x [ 6525.787760] CPU: 3 PID: 7881 Comm: test_verifier Tainted: G W 5.9.0-rc1+ #47 [ 6525.796111] Hardware name: Socionext SynQuacer E-series DeveloperBox, BIOS build #1 Jun 6 2020 [ 6525.804812] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--) [ 6525.810390] pc : bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.815613] lr : bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.820832] sp : ffff8000130cbb80 [ 6525.824141] x29: ffff8000130cbbb0 x28: 0000000000000000 [ 6525.829451] x27: 000005ef6fcbf39b x26: 0000000000000000 [ 6525.834759] x25: ffff8000130cbb80 x24: ffff800011dc7038 [ 6525.840067] x23: ffff8000130cbd00 x22: ffff0008f624d080 [ 6525.845375] x21: 0000000000000001 x20: ffff800011dc7000 [ 6525.850682] x19: 0000000000000000 x18: 0000000000000000 [ 6525.855990] x17: 0000000000000000 x16: 0000000000000000 [ 6525.861298] x15: 0000000000000000 x14: 0000000000000000 [ 6525.866606] x13: 0000000000000000 x12: 0000000000000000 [ 6525.871913] x11: 0000000000000001 x10: ffff8000000a660c [ 6525.877220] x9 : ffff800010951810 x8 : ffff8000130cbc38 [ 6525.882528] x7 : 0000000000000000 x6 : 0000009864cfa881 [ 6525.887836] x5 : 00ffffffffffffff x4 : 002880ba1a0b3e9f [ 6525.893144] x3 : 0000000000000018 x2 : ffff8000000a4374 [ 6525.898452] x1 : 000000000000000a x0 : 0000000000000009 [ 6525.903760] Call trace: [ 6525.906202] bpf_prog_c3d01833289b6311_F+0xc8/0x9f4 [ 6525.911076] bpf_prog_d53bb52e3f4483f9_F+0x38/0xc8c [ 6525.915957] bpf_dispatcher_xdp_func+0x14/0x20 [ 6525.920398] bpf_test_run+0x70/0x1b0 [ 6525.923969] bpf_prog_test_run_xdp+0xec/0x190 [ 6525.928326] __do_sys_bpf+0xc88/0x1b28 [ 6525.932072] __arm64_sys_bpf+0x24/0x30 [ 6525.935820] el0_svc_common.constprop.0+0x70/0x168 [ 6525.940607] do_el0_svc+0x28/0x88 [ 6525.943920] el0_sync_handler+0x88/0x190 [ 6525.947838] el0_sync+0x140/0x180 [ 6525.951154] Code: d4202000 d4202000 d4202000 d4202000 (d4202000) [ 6525.957249] ---[ end trace cecc3f93b14927e2 ]--- The reason is the offset[] creation and later usage while building the eBPF body. The code currently omits the first instruction, since build_insn() will increase our ctx->idx before saving it. That was fine up until bounded eBPF loops were introduced. After that introduction, offset[0] must be the offset of the end of prologue which is the start of the 1st insn while, offset[n] holds the offset of the end of n-th insn. When "taken loop with back jump to 1st insn" test runs, it will eventually call bpf2a64_offset(-1, 2, ctx). Since negative indexing is permitted, the current outcome depends on the value stored in ctx->offset[-1], which has nothing to do with our array. If the value happens to be 0 the tests will work. If not this error triggers. 7c2e988 ("bpf: fix x64 JIT code generation for jmp to 1st insn") fixed an indentical bug on x86 when eBPF bounded loops were introduced. So let's fix it by creating the ctx->offset[] correctly in the first place and account for the first instruction while calculating the arm instruction offsets. Fixes: 2589726 ("bpf: introduce bounded loops") Reported-by: Naresh Kamboju <[email protected]> Reported-by: Jiri Olsa <[email protected]> Co-developed-by: Jean-Philippe Brucker <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Co-developed-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Yauheni Kaliuta <[email protected]> Signed-off-by: Ilias Apalodimas <[email protected]> --- Changes since v1: - Added Co-developed-by, Reported-by and Fixes tags correctly - Describe the expected context of ctx->offset[] in comments arch/arm64/net/bpf_jit_comp.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 28, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 28, 2025
Removing a peer while userspace attempts to close its transport socket triggers a race condition resulting in the following crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000077: 0000 [kernel-patches#1] SMP KASAN KASAN: null-ptr-deref in range [0x00000000000003b8-0x00000000000003bf] CPU: 12 UID: 0 PID: 162 Comm: kworker/12:1 Tainted: G O 6.15.0-rc2-00635-g521139ac3840 kernel-patches#272 PREEMPT(full) Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-20240910_120124-localhost 04/01/2014 Workqueue: events ovpn_peer_keepalive_work [ovpn] RIP: 0010:ovpn_socket_release+0x23c/0x500 [ovpn] Code: ea 03 80 3c 02 00 0f 85 71 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d bc 24 be 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 30 RSP: 0018:ffffc90000c9fb18 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: ffff8881148d7940 RCX: ffffffff817787bb RDX: 0000000000000077 RSI: 0000000000000008 RDI: 00000000000003be RBP: ffffc90000c9fb30 R08: 0000000000000000 R09: fffffbfff0d3e840 R10: ffffffff869f4207 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888115eb9300 R14: ffffc90000c9fbc8 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8882b0151000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37266b6114 CR3: 00000000054a8000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> unlock_ovpn+0x8b/0xe0 [ovpn] ovpn_peer_keepalive_work+0xe3/0x540 [ovpn] ? ovpn_peers_free+0x780/0x780 [ovpn] ? lock_acquire+0x56/0x70 ? process_one_work+0x888/0x1740 process_one_work+0x933/0x1740 ? pwq_dec_nr_in_flight+0x10b0/0x10b0 ? move_linked_works+0x12d/0x2c0 ? assign_work+0x163/0x270 worker_thread+0x4d6/0xd90 ? preempt_count_sub+0x4c/0x70 ? process_one_work+0x1740/0x1740 kthread+0x36c/0x710 ? trace_preempt_on+0x8c/0x1e0 ? kthread_is_per_cpu+0xc0/0xc0 ? preempt_count_sub+0x4c/0x70 ? _raw_spin_unlock_irq+0x36/0x60 ? calculate_sigpending+0x7b/0xa0 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x80 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork_asm+0x11/0x20 </TASK> Modules linked in: ovpn(O) This happens because the peer deletion operation reaches ovpn_socket_release() while ovpn_sock->sock (struct socket *) and its sk member (struct sock *) are still both valid. Here synchronize_rcu() is invoked, after which ovpn_sock->sock->sk becomes NULL, due to the concurrent socket closing triggered from userspace. After having invoked synchronize_rcu(), ovpn_socket_release() will attempt dereferencing ovpn_sock->sock->sk, triggering the crash reported above. The reason for accessing sk is that we need to retrieve its protocol and continue the cleanup routine accordingly. This crash can be easily produced by running openvpn userspace in client mode with `--keepalive 10 20`, while entirely omitting this option on the server side. After 20 seconds ovpn will assume the peer (server) to be dead, will start removing it and will notify userspace. The latter will receive the notification and close the transport socket, thus triggering the crash. To fix the race condition for good, we need to refactor struct ovpn_socket. Since ovpn is always only interested in the sock->sk member (struct sock *) we can directly hold a reference to it, raher than accessing it via its struct socket container. This means changing "struct socket *ovpn_socket->sock" to "struct sock *ovpn_socket->sk". While acquiring a reference to sk, we can increase its refcounter without affecting the socket close()/destroy() notification (which we rely on when userspace closes a socket we are using). By increasing sk's refcounter we know we can dereference it in ovpn_socket_release() without incurring in any race condition anymore. ovpn_socket_release() will ultimately decrease the reference counter. Cc: Oleksandr Natalenko <[email protected]> Fixes: 11851cb ("ovpn: implement TCP transport") Reported-by: Qingfang Deng <[email protected]> Closes: OpenVPN/ovpn-net-next#1 Tested-by: Gert Doering <[email protected]> Link: https://www.mail-archive.com/[email protected]/msg31575.html Signed-off-by: Antonio Quartulli <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 28, 2025
Detect invalid geometry due to pull from frag_list, and pass to
regular skb_segment. If only part of the fraglist payload is pulled
into head_skb, it will always cause exception when splitting
skbs by skb_segment. For detailed call stack information, see below.
Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size
Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify fraglist skbs, breaking these invariants.
In extreme cases they pull one part of data into skb linear. For UDP,
this causes three payloads with lengths of (11,11,10) bytes were
pulled tail to become (12,10,10) bytes.
The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because
payload was pulled into head_skb, it needs to be linearized before pass
to regular skb_segment.
skb_segment+0xcd0/0xd14
__udp_gso_segment+0x334/0x5f4
udp4_ufo_fragment+0x118/0x15c
inet_gso_segment+0x164/0x338
skb_mac_gso_segment+0xc4/0x13c
__skb_gso_segment+0xc4/0x124
validate_xmit_skb+0x9c/0x2c0
validate_xmit_skb_list+0x4c/0x80
sch_direct_xmit+0x70/0x404
__dev_queue_xmit+0x64c/0xe5c
neigh_resolve_output+0x178/0x1c4
ip_finish_output2+0x37c/0x47c
__ip_finish_output+0x194/0x240
ip_finish_output+0x20/0xf4
ip_output+0x100/0x1a0
NF_HOOK+0xc4/0x16c
ip_forward+0x314/0x32c
ip_rcv+0x90/0x118
__netif_receive_skb+0x74/0x124
process_backlog+0xe8/0x1a4
__napi_poll+0x5c/0x1f8
net_rx_action+0x154/0x314
handle_softirqs+0x154/0x4b8
[118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278!
[118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP
[118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000
[118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000
[118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO)
[118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14
[118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14
[118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770
Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list")
Signed-off-by: Shiming Cheng <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 28, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Removing a peer while userspace attempts to close its transport socket triggers a race condition resulting in the following crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000077: 0000 [kernel-patches#1] SMP KASAN KASAN: null-ptr-deref in range [0x00000000000003b8-0x00000000000003bf] CPU: 12 UID: 0 PID: 162 Comm: kworker/12:1 Tainted: G O 6.15.0-rc2-00635-g521139ac3840 kernel-patches#272 PREEMPT(full) Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-20240910_120124-localhost 04/01/2014 Workqueue: events ovpn_peer_keepalive_work [ovpn] RIP: 0010:ovpn_socket_release+0x23c/0x500 [ovpn] Code: ea 03 80 3c 02 00 0f 85 71 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d bc 24 be 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 30 RSP: 0018:ffffc90000c9fb18 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: ffff8881148d7940 RCX: ffffffff817787bb RDX: 0000000000000077 RSI: 0000000000000008 RDI: 00000000000003be RBP: ffffc90000c9fb30 R08: 0000000000000000 R09: fffffbfff0d3e840 R10: ffffffff869f4207 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888115eb9300 R14: ffffc90000c9fbc8 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8882b0151000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37266b6114 CR3: 00000000054a8000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> unlock_ovpn+0x8b/0xe0 [ovpn] ovpn_peer_keepalive_work+0xe3/0x540 [ovpn] ? ovpn_peers_free+0x780/0x780 [ovpn] ? lock_acquire+0x56/0x70 ? process_one_work+0x888/0x1740 process_one_work+0x933/0x1740 ? pwq_dec_nr_in_flight+0x10b0/0x10b0 ? move_linked_works+0x12d/0x2c0 ? assign_work+0x163/0x270 worker_thread+0x4d6/0xd90 ? preempt_count_sub+0x4c/0x70 ? process_one_work+0x1740/0x1740 kthread+0x36c/0x710 ? trace_preempt_on+0x8c/0x1e0 ? kthread_is_per_cpu+0xc0/0xc0 ? preempt_count_sub+0x4c/0x70 ? _raw_spin_unlock_irq+0x36/0x60 ? calculate_sigpending+0x7b/0xa0 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x80 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork_asm+0x11/0x20 </TASK> Modules linked in: ovpn(O) This happens because the peer deletion operation reaches ovpn_socket_release() while ovpn_sock->sock (struct socket *) and its sk member (struct sock *) are still both valid. Here synchronize_rcu() is invoked, after which ovpn_sock->sock->sk becomes NULL, due to the concurrent socket closing triggered from userspace. After having invoked synchronize_rcu(), ovpn_socket_release() will attempt dereferencing ovpn_sock->sock->sk, triggering the crash reported above. The reason for accessing sk is that we need to retrieve its protocol and continue the cleanup routine accordingly. This crash can be easily produced by running openvpn userspace in client mode with `--keepalive 10 20`, while entirely omitting this option on the server side. After 20 seconds ovpn will assume the peer (server) to be dead, will start removing it and will notify userspace. The latter will receive the notification and close the transport socket, thus triggering the crash. To fix the race condition for good, we need to refactor struct ovpn_socket. Since ovpn is always only interested in the sock->sk member (struct sock *) we can directly hold a reference to it, raher than accessing it via its struct socket container. This means changing "struct socket *ovpn_socket->sock" to "struct sock *ovpn_socket->sk". While acquiring a reference to sk, we can increase its refcounter without affecting the socket close()/destroy() notification (which we rely on when userspace closes a socket we are using). By increasing sk's refcounter we know we can dereference it in ovpn_socket_release() without incurring in any race condition anymore. ovpn_socket_release() will ultimately decrease the reference counter. Cc: Oleksandr Natalenko <[email protected]> Fixes: 11851cb ("ovpn: implement TCP transport") Reported-by: Qingfang Deng <[email protected]> Closes: OpenVPN/ovpn-net-next#1 Tested-by: Gert Doering <[email protected]> Link: https://www.mail-archive.com/[email protected]/msg31575.html Signed-off-by: Antonio Quartulli <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Detect invalid geometry due to pull from frag_list, and pass to
regular skb_segment. If only part of the fraglist payload is pulled
into head_skb, it will always cause exception when splitting
skbs by skb_segment. For detailed call stack information, see below.
Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size
Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify fraglist skbs, breaking these invariants.
In extreme cases they pull one part of data into skb linear. For UDP,
this causes three payloads with lengths of (11,11,10) bytes were
pulled tail to become (12,10,10) bytes.
The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because
payload was pulled into head_skb, it needs to be linearized before pass
to regular skb_segment.
skb_segment+0xcd0/0xd14
__udp_gso_segment+0x334/0x5f4
udp4_ufo_fragment+0x118/0x15c
inet_gso_segment+0x164/0x338
skb_mac_gso_segment+0xc4/0x13c
__skb_gso_segment+0xc4/0x124
validate_xmit_skb+0x9c/0x2c0
validate_xmit_skb_list+0x4c/0x80
sch_direct_xmit+0x70/0x404
__dev_queue_xmit+0x64c/0xe5c
neigh_resolve_output+0x178/0x1c4
ip_finish_output2+0x37c/0x47c
__ip_finish_output+0x194/0x240
ip_finish_output+0x20/0xf4
ip_output+0x100/0x1a0
NF_HOOK+0xc4/0x16c
ip_forward+0x314/0x32c
ip_rcv+0x90/0x118
__netif_receive_skb+0x74/0x124
process_backlog+0xe8/0x1a4
__napi_poll+0x5c/0x1f8
net_rx_action+0x154/0x314
handle_softirqs+0x154/0x4b8
[118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278!
[118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP
[118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000
[118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000
[118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO)
[118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14
[118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14
[118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770
Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list")
Signed-off-by: Shiming Cheng <[email protected]>
Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kernel-patches-daemon-bpf bot
pushed a commit
that referenced
this pull request
May 29, 2025
…ugetlb folios A kernel crash was observed when replacing free hugetlb folios: BUG: kernel NULL pointer dereference, address: 0000000000000028 PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 28 UID: 0 PID: 29639 Comm: test_cma.sh Tainted 6.15.0-rc6-zp #41 PREEMPT(voluntary) RIP: 0010:alloc_and_dissolve_hugetlb_folio+0x1d/0x1f0 RSP: 0018:ffffc9000b30fa90 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000342cca RCX: ffffea0043000000 RDX: ffffc9000b30fb08 RSI: ffffea0043000000 RDI: 0000000000000000 RBP: ffffc9000b30fb20 R08: 0000000000001000 R09: 0000000000000000 R10: ffff88886f92eb00 R11: 0000000000000000 R12: ffffea0043000000 R13: 0000000000000000 R14: 00000000010c0200 R15: 0000000000000004 FS: 00007fcda5f14740(0000) GS:ffff8888ec1d8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000028 CR3: 0000000391402000 CR4: 0000000000350ef0 Call Trace: <TASK> replace_free_hugepage_folios+0xb6/0x100 alloc_contig_range_noprof+0x18a/0x590 ? srso_return_thunk+0x5/0x5f ? down_read+0x12/0xa0 ? srso_return_thunk+0x5/0x5f cma_range_alloc.constprop.0+0x131/0x290 __cma_alloc+0xcf/0x2c0 cma_alloc_write+0x43/0xb0 simple_attr_write_xsigned.constprop.0.isra.0+0xb2/0x110 debugfs_attr_write+0x46/0x70 full_proxy_write+0x62/0xa0 vfs_write+0xf8/0x420 ? srso_return_thunk+0x5/0x5f ? filp_flush+0x86/0xa0 ? srso_return_thunk+0x5/0x5f ? filp_close+0x1f/0x30 ? srso_return_thunk+0x5/0x5f ? do_dup2+0xaf/0x160 ? srso_return_thunk+0x5/0x5f ksys_write+0x65/0xe0 do_syscall_64+0x64/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e There is a potential race between __update_and_free_hugetlb_folio() and replace_free_hugepage_folios(): CPU1 CPU2 __update_and_free_hugetlb_folio replace_free_hugepage_folios folio_test_hugetlb(folio) -- It's still hugetlb folio. __folio_clear_hugetlb(folio) hugetlb_free_folio(folio) h = folio_hstate(folio) -- Here, h is NULL pointer When the above race condition occurs, folio_hstate(folio) returns NULL, and subsequent access to this NULL pointer will cause the system to crash. To resolve this issue, execute folio_hstate(folio) under the protection of the hugetlb_lock lock, ensuring that folio_hstate(folio) does not return NULL. Link: https://lkml.kernel.org/r/[email protected] Fixes: 04f13d2 ("mm: replace free hugepage folios after migration") Signed-off-by: Ge Yang <[email protected]> Reviewed-by: Muchun Song <[email protected]> Reviewed-by: Oscar Salvador <[email protected]> Cc: Baolin Wang <[email protected]> Cc: Barry Song <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Removing a peer while userspace attempts to close its transport socket triggers a race condition resulting in the following crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000077: 0000 [kernel-patches#1] SMP KASAN KASAN: null-ptr-deref in range [0x00000000000003b8-0x00000000000003bf] CPU: 12 UID: 0 PID: 162 Comm: kworker/12:1 Tainted: G O 6.15.0-rc2-00635-g521139ac3840 kernel-patches#272 PREEMPT(full) Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-20240910_120124-localhost 04/01/2014 Workqueue: events ovpn_peer_keepalive_work [ovpn] RIP: 0010:ovpn_socket_release+0x23c/0x500 [ovpn] Code: ea 03 80 3c 02 00 0f 85 71 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d bc 24 be 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 30 RSP: 0018:ffffc90000c9fb18 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: ffff8881148d7940 RCX: ffffffff817787bb RDX: 0000000000000077 RSI: 0000000000000008 RDI: 00000000000003be RBP: ffffc90000c9fb30 R08: 0000000000000000 R09: fffffbfff0d3e840 R10: ffffffff869f4207 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888115eb9300 R14: ffffc90000c9fbc8 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8882b0151000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37266b6114 CR3: 00000000054a8000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> unlock_ovpn+0x8b/0xe0 [ovpn] ovpn_peer_keepalive_work+0xe3/0x540 [ovpn] ? ovpn_peers_free+0x780/0x780 [ovpn] ? lock_acquire+0x56/0x70 ? process_one_work+0x888/0x1740 process_one_work+0x933/0x1740 ? pwq_dec_nr_in_flight+0x10b0/0x10b0 ? move_linked_works+0x12d/0x2c0 ? assign_work+0x163/0x270 worker_thread+0x4d6/0xd90 ? preempt_count_sub+0x4c/0x70 ? process_one_work+0x1740/0x1740 kthread+0x36c/0x710 ? trace_preempt_on+0x8c/0x1e0 ? kthread_is_per_cpu+0xc0/0xc0 ? preempt_count_sub+0x4c/0x70 ? _raw_spin_unlock_irq+0x36/0x60 ? calculate_sigpending+0x7b/0xa0 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x80 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork_asm+0x11/0x20 </TASK> Modules linked in: ovpn(O) This happens because the peer deletion operation reaches ovpn_socket_release() while ovpn_sock->sock (struct socket *) and its sk member (struct sock *) are still both valid. Here synchronize_rcu() is invoked, after which ovpn_sock->sock->sk becomes NULL, due to the concurrent socket closing triggered from userspace. After having invoked synchronize_rcu(), ovpn_socket_release() will attempt dereferencing ovpn_sock->sock->sk, triggering the crash reported above. The reason for accessing sk is that we need to retrieve its protocol and continue the cleanup routine accordingly. This crash can be easily produced by running openvpn userspace in client mode with `--keepalive 10 20`, while entirely omitting this option on the server side. After 20 seconds ovpn will assume the peer (server) to be dead, will start removing it and will notify userspace. The latter will receive the notification and close the transport socket, thus triggering the crash. To fix the race condition for good, we need to refactor struct ovpn_socket. Since ovpn is always only interested in the sock->sk member (struct sock *) we can directly hold a reference to it, raher than accessing it via its struct socket container. This means changing "struct socket *ovpn_socket->sock" to "struct sock *ovpn_socket->sk". While acquiring a reference to sk, we can increase its refcounter without affecting the socket close()/destroy() notification (which we rely on when userspace closes a socket we are using). By increasing sk's refcounter we know we can dereference it in ovpn_socket_release() without incurring in any race condition anymore. ovpn_socket_release() will ultimately decrease the reference counter. Cc: Oleksandr Natalenko <[email protected]> Fixes: 11851cb ("ovpn: implement TCP transport") Reported-by: Qingfang Deng <[email protected]> Closes: OpenVPN/ovpn-net-next#1 Tested-by: Gert Doering <[email protected]> Link: https://www.mail-archive.com/[email protected]/msg31575.html Signed-off-by: Antonio Quartulli <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Removing a peer while userspace attempts to close its transport socket triggers a race condition resulting in the following crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000077: 0000 [kernel-patches#1] SMP KASAN KASAN: null-ptr-deref in range [0x00000000000003b8-0x00000000000003bf] CPU: 12 UID: 0 PID: 162 Comm: kworker/12:1 Tainted: G O 6.15.0-rc2-00635-g521139ac3840 kernel-patches#272 PREEMPT(full) Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-20240910_120124-localhost 04/01/2014 Workqueue: events ovpn_peer_keepalive_work [ovpn] RIP: 0010:ovpn_socket_release+0x23c/0x500 [ovpn] Code: ea 03 80 3c 02 00 0f 85 71 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d bc 24 be 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 30 RSP: 0018:ffffc90000c9fb18 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: ffff8881148d7940 RCX: ffffffff817787bb RDX: 0000000000000077 RSI: 0000000000000008 RDI: 00000000000003be RBP: ffffc90000c9fb30 R08: 0000000000000000 R09: fffffbfff0d3e840 R10: ffffffff869f4207 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888115eb9300 R14: ffffc90000c9fbc8 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8882b0151000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37266b6114 CR3: 00000000054a8000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> unlock_ovpn+0x8b/0xe0 [ovpn] ovpn_peer_keepalive_work+0xe3/0x540 [ovpn] ? ovpn_peers_free+0x780/0x780 [ovpn] ? lock_acquire+0x56/0x70 ? process_one_work+0x888/0x1740 process_one_work+0x933/0x1740 ? pwq_dec_nr_in_flight+0x10b0/0x10b0 ? move_linked_works+0x12d/0x2c0 ? assign_work+0x163/0x270 worker_thread+0x4d6/0xd90 ? preempt_count_sub+0x4c/0x70 ? process_one_work+0x1740/0x1740 kthread+0x36c/0x710 ? trace_preempt_on+0x8c/0x1e0 ? kthread_is_per_cpu+0xc0/0xc0 ? preempt_count_sub+0x4c/0x70 ? _raw_spin_unlock_irq+0x36/0x60 ? calculate_sigpending+0x7b/0xa0 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x80 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork_asm+0x11/0x20 </TASK> Modules linked in: ovpn(O) This happens because the peer deletion operation reaches ovpn_socket_release() while ovpn_sock->sock (struct socket *) and its sk member (struct sock *) are still both valid. Here synchronize_rcu() is invoked, after which ovpn_sock->sock->sk becomes NULL, due to the concurrent socket closing triggered from userspace. After having invoked synchronize_rcu(), ovpn_socket_release() will attempt dereferencing ovpn_sock->sock->sk, triggering the crash reported above. The reason for accessing sk is that we need to retrieve its protocol and continue the cleanup routine accordingly. This crash can be easily produced by running openvpn userspace in client mode with `--keepalive 10 20`, while entirely omitting this option on the server side. After 20 seconds ovpn will assume the peer (server) to be dead, will start removing it and will notify userspace. The latter will receive the notification and close the transport socket, thus triggering the crash. To fix the race condition for good, we need to refactor struct ovpn_socket. Since ovpn is always only interested in the sock->sk member (struct sock *) we can directly hold a reference to it, raher than accessing it via its struct socket container. This means changing "struct socket *ovpn_socket->sock" to "struct sock *ovpn_socket->sk". While acquiring a reference to sk, we can increase its refcounter without affecting the socket close()/destroy() notification (which we rely on when userspace closes a socket we are using). By increasing sk's refcounter we know we can dereference it in ovpn_socket_release() without incurring in any race condition anymore. ovpn_socket_release() will ultimately decrease the reference counter. Cc: Oleksandr Natalenko <[email protected]> Fixes: 11851cb ("ovpn: implement TCP transport") Reported-by: Qingfang Deng <[email protected]> Closes: OpenVPN/ovpn-net-next#1 Tested-by: Gert Doering <[email protected]> Link: https://www.mail-archive.com/[email protected]/msg31575.html Signed-off-by: Antonio Quartulli <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 29, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Removing a peer while userspace attempts to close its transport socket triggers a race condition resulting in the following crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000077: 0000 [kernel-patches#1] SMP KASAN KASAN: null-ptr-deref in range [0x00000000000003b8-0x00000000000003bf] CPU: 12 UID: 0 PID: 162 Comm: kworker/12:1 Tainted: G O 6.15.0-rc2-00635-g521139ac3840 kernel-patches#272 PREEMPT(full) Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-20240910_120124-localhost 04/01/2014 Workqueue: events ovpn_peer_keepalive_work [ovpn] RIP: 0010:ovpn_socket_release+0x23c/0x500 [ovpn] Code: ea 03 80 3c 02 00 0f 85 71 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d bc 24 be 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 30 RSP: 0018:ffffc90000c9fb18 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: ffff8881148d7940 RCX: ffffffff817787bb RDX: 0000000000000077 RSI: 0000000000000008 RDI: 00000000000003be RBP: ffffc90000c9fb30 R08: 0000000000000000 R09: fffffbfff0d3e840 R10: ffffffff869f4207 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888115eb9300 R14: ffffc90000c9fbc8 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8882b0151000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37266b6114 CR3: 00000000054a8000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> unlock_ovpn+0x8b/0xe0 [ovpn] ovpn_peer_keepalive_work+0xe3/0x540 [ovpn] ? ovpn_peers_free+0x780/0x780 [ovpn] ? lock_acquire+0x56/0x70 ? process_one_work+0x888/0x1740 process_one_work+0x933/0x1740 ? pwq_dec_nr_in_flight+0x10b0/0x10b0 ? move_linked_works+0x12d/0x2c0 ? assign_work+0x163/0x270 worker_thread+0x4d6/0xd90 ? preempt_count_sub+0x4c/0x70 ? process_one_work+0x1740/0x1740 kthread+0x36c/0x710 ? trace_preempt_on+0x8c/0x1e0 ? kthread_is_per_cpu+0xc0/0xc0 ? preempt_count_sub+0x4c/0x70 ? _raw_spin_unlock_irq+0x36/0x60 ? calculate_sigpending+0x7b/0xa0 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x80 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork_asm+0x11/0x20 </TASK> Modules linked in: ovpn(O) This happens because the peer deletion operation reaches ovpn_socket_release() while ovpn_sock->sock (struct socket *) and its sk member (struct sock *) are still both valid. Here synchronize_rcu() is invoked, after which ovpn_sock->sock->sk becomes NULL, due to the concurrent socket closing triggered from userspace. After having invoked synchronize_rcu(), ovpn_socket_release() will attempt dereferencing ovpn_sock->sock->sk, triggering the crash reported above. The reason for accessing sk is that we need to retrieve its protocol and continue the cleanup routine accordingly. This crash can be easily produced by running openvpn userspace in client mode with `--keepalive 10 20`, while entirely omitting this option on the server side. After 20 seconds ovpn will assume the peer (server) to be dead, will start removing it and will notify userspace. The latter will receive the notification and close the transport socket, thus triggering the crash. To fix the race condition for good, we need to refactor struct ovpn_socket. Since ovpn is always only interested in the sock->sk member (struct sock *) we can directly hold a reference to it, raher than accessing it via its struct socket container. This means changing "struct socket *ovpn_socket->sock" to "struct sock *ovpn_socket->sk". While acquiring a reference to sk, we can increase its refcounter without affecting the socket close()/destroy() notification (which we rely on when userspace closes a socket we are using). By increasing sk's refcounter we know we can dereference it in ovpn_socket_release() without incurring in any race condition anymore. ovpn_socket_release() will ultimately decrease the reference counter. Cc: Oleksandr Natalenko <[email protected]> Fixes: 11851cb ("ovpn: implement TCP transport") Reported-by: Qingfang Deng <[email protected]> Closes: OpenVPN/ovpn-net-next#1 Tested-by: Gert Doering <[email protected]> Link: https://www.mail-archive.com/[email protected]/msg31575.html Signed-off-by: Antonio Quartulli <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Commit a1e40ac ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [kernel-patches#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac ("gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [kernel-patches#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <[email protected]> Signed-off-by: NipaLocal <nipa@local>
kuba-moo
pushed a commit
to linux-netdev/testing-bpf-ci
that referenced
this pull request
May 30, 2025
Removing a peer while userspace attempts to close its transport socket triggers a race condition resulting in the following crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000077: 0000 [kernel-patches#1] SMP KASAN KASAN: null-ptr-deref in range [0x00000000000003b8-0x00000000000003bf] CPU: 12 UID: 0 PID: 162 Comm: kworker/12:1 Tainted: G O 6.15.0-rc2-00635-g521139ac3840 kernel-patches#272 PREEMPT(full) Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-20240910_120124-localhost 04/01/2014 Workqueue: events ovpn_peer_keepalive_work [ovpn] RIP: 0010:ovpn_socket_release+0x23c/0x500 [ovpn] Code: ea 03 80 3c 02 00 0f 85 71 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 18 49 8d bc 24 be 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 30 RSP: 0018:ffffc90000c9fb18 EFLAGS: 00010217 RAX: dffffc0000000000 RBX: ffff8881148d7940 RCX: ffffffff817787bb RDX: 0000000000000077 RSI: 0000000000000008 RDI: 00000000000003be RBP: ffffc90000c9fb30 R08: 0000000000000000 R09: fffffbfff0d3e840 R10: ffffffff869f4207 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888115eb9300 R14: ffffc90000c9fbc8 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8882b0151000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37266b6114 CR3: 00000000054a8000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> unlock_ovpn+0x8b/0xe0 [ovpn] ovpn_peer_keepalive_work+0xe3/0x540 [ovpn] ? ovpn_peers_free+0x780/0x780 [ovpn] ? lock_acquire+0x56/0x70 ? process_one_work+0x888/0x1740 process_one_work+0x933/0x1740 ? pwq_dec_nr_in_flight+0x10b0/0x10b0 ? move_linked_works+0x12d/0x2c0 ? assign_work+0x163/0x270 worker_thread+0x4d6/0xd90 ? preempt_count_sub+0x4c/0x70 ? process_one_work+0x1740/0x1740 kthread+0x36c/0x710 ? trace_preempt_on+0x8c/0x1e0 ? kthread_is_per_cpu+0xc0/0xc0 ? preempt_count_sub+0x4c/0x70 ? _raw_spin_unlock_irq+0x36/0x60 ? calculate_sigpending+0x7b/0xa0 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x80 ? kthread_is_per_cpu+0xc0/0xc0 ret_from_fork_asm+0x11/0x20 </TASK> Modules linked in: ovpn(O) This happens because the peer deletion operation reaches ovpn_socket_release() while ovpn_sock->sock (struct socket *) and its sk member (struct sock *) are still both valid. Here synchronize_rcu() is invoked, after which ovpn_sock->sock->sk becomes NULL, due to the concurrent socket closing triggered from userspace. After having invoked synchronize_rcu(), ovpn_socket_release() will attempt dereferencing ovpn_sock->sock->sk, triggering the crash reported above. The reason for accessing sk is that we need to retrieve its protocol and continue the cleanup routine accordingly. This crash can be easily produced by running openvpn userspace in client mode with `--keepalive 10 20`, while entirely omitting this option on the server side. After 20 seconds ovpn will assume the peer (server) to be dead, will start removing it and will notify userspace. The latter will receive the notification and close the transport socket, thus triggering the crash. To fix the race condition for good, we need to refactor struct ovpn_socket. Since ovpn is always only interested in the sock->sk member (struct sock *) we can directly hold a reference to it, raher than accessing it via its struct socket container. This means changing "struct socket *ovpn_socket->sock" to "struct sock *ovpn_socket->sk". While acquiring a reference to sk, we can increase its refcounter without affecting the socket close()/destroy() notification (which we rely on when userspace closes a socket we are using). By increasing sk's refcounter we know we can dereference it in ovpn_socket_release() without incurring in any race condition anymore. ovpn_socket_release() will ultimately decrease the reference counter. Cc: Oleksandr Natalenko <[email protected]> Fixes: 11851cb ("ovpn: implement TCP transport") Reported-by: Qingfang Deng <[email protected]> Closes: OpenVPN/ovpn-net-next#1 Tested-by: Gert Doering <[email protected]> Link: https://www.mail-archive.com/[email protected]/msg31575.html Signed-off-by: Antonio Quartulli <[email protected]> Signed-off-by: NipaLocal <nipa@local>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Pull request for series with
subject: bpf: BTF support for ksyms
version: 2
url: https://patchwork.ozlabs.org/project/netdev/list/?series=199405